PREPARATION

Bring broth to a boil in a large soup pot over medium-high, then stir in zest, bay leaves and onion. Add chicken, reduce heat to low and simmer 10 minutes. Remove chicken and cool before cutting into bite-size pieces. Return soup to a boil, then stir in escarole and chicken pieces. Reduce heat and simmer, covered, another 5 minutes. Remove bay leaves. Salt and pepper; garnish each bowl with 1 tbsp Parmesan.